1. Field of the Invention
The invention relates generally to electrical switching apparatus and, more particularly, to charging assemblies for electrical switching apparatus, such as circuit breakers. The invention also relates to charging handles for circuit breaker charging mechanisms.
2. Background Information
Electrical switching apparatus, such as circuit breakers, provide protection for electrical systems from electrical fault conditions such as, for example, current overloads, short circuits, abnormal voltage and other fault conditions. Typically, circuit breakers include an operating mechanism which opens electrical contact assemblies to interrupt the flow of current through the conductors of an electrical system in response to such fault conditions.
Many low-voltage circuit breakers, for example, employ a molded housing having a cover. The operating mechanism for such circuit breakers is structured to open and close separable electrical contacts, which are enclosed by the molded housing. More specifically, the operating mechanism includes a charging assembly having a close spring and a charging handle. The close spring stores energy for closing the circuit breaker, and is charged by pulling the charging handle a number of times. When the charging handle is not being employed, it is typically stowed in an upright position within a recess in the cover of the circuit breaker housing, and is held there by a handle return spring. Low-voltage circuit breakers and charging assemblies therefor are described, in detail, for example, in U.S. Pat. Nos. 5,938,008, 6,064,021, and 6,160,234, which are incorporated herein by reference.
It can be difficult for an operator to gain the necessary access to the charging handle (e.g., insert a finger underneath the handle) to remove (e.g., pivot it far enough with respect to the housing cover) it from the recess and have access to a sufficient portion of the charging handle to grasp it and begin the charging operation. Additionally, known charging handles for charging circuit breaker operating mechanisms tend to be relatively narrow, and often have relatively abrupt (e.g., sharp) edges. This can cause discomfort to the operator when the operator pulls on the handle and experiences the load associated with charging the breaker. These disadvantages are particularly pronounced in view of the market trend toward smaller circuit breakers. Specifically, the relatively small size of circuit breakers inhibits the ability to quickly, easily and relatively comfortably operate the user interface features of the circuit breaker, including the charging handle. Added to this is the fact that the individuals (e.g., without limitation, electricians) who typically operate the circuit breakers sometimes prefer or insist on wearing work gloves, which can make manipulation of the charging handle very difficult.
In an attempt to overcome this disadvantage, one prior proposal has been to include a molded finger recess in the cover of the circuit breaker housing. Specifically, a recess is provided as a molded feature extending from the outer surface of the housing cover and protruding into the interior of the housing. The recess is intended to be deep enough for the operator to reach his or her finger underneath the end of the charging handle. However, this undesirably results in the recess protruding a significant distance into the interior of the circuit breaker housing and taking up valuable space therein. Another disadvantage is that such recesses tend to favor either right-handed or left-handed operators by providing access to only one of the left and right sides of the charging handle. See, e.g., U.S. Pat. Nos. 5,938,008, 6,064,021, and 6,160,234 (each showing a recess for a charging handle which provides access only to the right side of the charging handle).
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in charging assemblies and charging handles therefor.